Multidigit number comparing device



March 1950 E. KOUZMINE MULTIDIGIT NUMBER-COMPARING DEVICE Filed July 17, 1947 x MN & INVENTOR EUGENE KOUZM/NE W ATTORNEY Patented Mar. 28, 1950 2,501,821 MULTIDIGIT NUMBER CUMPARING DEVICE Eugene Kouzmine, Paris, France, assignor to International Business Machines Corporation,

New York, N. "5. a corporation of New York Application July 17, 1947, Serial No. 761,629 In France February 15, 1944 Section 1, Public Law 690, August 8, 1946 Patent expires February 15, 1954 4 Claims.

The present invention relates to devices for comparing two numbers to ascertain their relative magnitudes. The invention has particular application to calculating machines in which registers are provided upon which numbers are set as a result of entries made from record cards or key sources. In the type of calculation machine wherein dividing operations are carried out, provision is generally made for setting up on a register a number representing a dividend and 1 another register is set to represent a divisor, and it is desirable to ascertain the relationship between these two factors.

It is well known in calculating machines that a register may be set up to represent a dividend and a plurality oi: other registers may be set up each representing a different multiple of the divisor, so that concurrent comparison may be made between the dividend and the various divisor multiples to ascertain the highest multiple that will go into the dividend.

The present invention contemplates the provision of a simplified apparatus that will effect comparison between a dividend amount and one or more divisor amounts, together with devices actuated in accordance with the result of the comparison.

Other characteristics and advantages of the present invention will also be made more evident on reading the following description and from an inspection of the drawing which is a diagram of the circuit arrangement for comparing one amount with one or more other amounts.

In the drawing:

Three denominational orders of the comparing mechanism are illustrated by way of example and designated DDR-h, DDRrt and DDRu. In the upper part of the drawing are shown three stationary arcuate conductors lZh, i212 and 12a, each of which has associated therewith ten socalled steps lflh, int and Wu. Within each set comprising a conductor and ten steps is a brush or wiper arrangement comprising a central wiper H71, Ht or Hu and two sets of multiple brushes such as i3h-a and I3h-b. This brush structure may be positioned angularly to represent any of the digits, and for purposes or" explanation the separate orders are generally designated DDR-h, DDRr-t, DDR-u to designate the hundreds, tens and units orders of a register upon which a dividend amount is set. For illustrative purposes, the dividend amount 516 is indicated as being set on these devices, which is done by positioning the central brush H in contact with the step It corresponding to the digit to be represented. Such positioning will cause all steps 10 of lower value to be electrically connected together through brushes l3h--a and all steps In of higher value to be connected together through brushes l3hb, as is apparent from inspection of the drawing.

For representing a second amount such as a divisor, angularly positionable brushes 25 are provided which may be positioned to connect any one of ten steps 24 to an arcuate conductor 26. Three of such devices for representing a three place divisor amount are designated generally as MLdR-la IViL iRr-i, MLQR1L. In the diagram this set of devices is set to represent the amount 424 and the brushes 25 thereof may be positioned automatically in known manner by the registers of a calculating machine. If further divisor amounts are to be considered, additional sets of brushes 25 and related steps 24 are provided as indicated. Thus, for example, on the set prefixed ML5R the value 516 is represented in the drawing and on the third set prefixed MLGR. the amount 608 is represented. For simplicity of the disclosure, only three divisor amount settings are provided, and it will be understood that where it is desired to compare a dividend amount with all nine multiples of a divisor, there will be nine sets of three brushes 25 and related contact devices.

In the hundreds order of the apparatus, the steps 2 3 are connected through the wires 28a, 2iib and At-c to a common set of wires 2's which extend to the steps lllh so that all like value steps are connected together. In the tens order similar connection through wires prefixed 3t and the group of wires 29 is made. Each of the common conductors 26 in the units and tens orders is connected to a pair of relay windings generally prefixed 4Q for the upper set, 5Q for the central set, and 6Q for the lowermost set. The two windings of each pair are on a common core. In the units order, the steps 24 are connected through wires prefixed 32 and a group of wires 3! to stops it with a one unit shift in their relationship. Thus, for example, the 9 wire 32 is connected to the 8 step It], the 8 wire 32 is connected to the 7 step H3, and so on.

For completing circuits through the apparatus, three terminals designated I6, 20 and 22 are provided which are at different electrical potentials, for example, 80, 40 and 0 volts, respectively, and

when contacts M and I5 are closed, circuits will be established in accordance with the relative values of the dividend and divisor as set on their respective sets of brushes.

In the hundreds or highest order position, the relay winding lQh-J) has a pair of contacts 4Qti in series therewith which are closed by relay iQt of the tens order when either of its windings receives current. The upper winding of each pair, for example, winding 4Qha has a unidirectional current fiow device designated 3? in series therewith.

Let us first consider a comparison of the dividend amount 516 with a divisor amount 424, and trace the specific circuits involved upon closure of contacts I and I5 which, for purposes of explanation, may be presumed to be closed manually after the values have been set on their re spective sets of brushes. A first circuit is traceable from the 80 volt source iii through contacts I 2, wire ll, contacts it, step lilh and through the brushes lib-u to the 4: step 9th, the 4 wire 27, the 4 wire 28-a, to the 4.- step 2 at which brush 25 is set in. the hundreds order, conductor upper winding lQh a, unidirectional current flow device Bl, wire 2i and contacts it to the 40 volt current source Zll.

It may be mentioned that contacts it in the hundreds order as well as contacts it and 23 in the two lower orders are normally closed and are opened through any suitable means when the dividend digit in the related order is 0. Thus, provision is made to prevent possible back circuit conditions.

In the tens order for the example under consideration, where the dividend digit is 1 and the divisor digit is 2, there will be no circuit completed since current is supplied from the 80 volt source to the contacts i l, thence through contacts Hi to the 0 step itt, whose 0 wire 29 extending to the 0 step 72 is not connected to the conductor 2t.

In the units order likewise, no circuit is ccmpleted since the wire it ending from the common conductor in th units order runs to coil tQt-b whose opposite side is connected to the conductor 2t in the tens order. Accordingly, for the chosen example where the dividend 516 is greater than divisor 42 i, relay i-Qh-a is energized and represents by such energization that the dividend is greater than the divisor. For simplicity in the disclosure, the device which is controlled by the relay upon energization is not illustrated.

Let us consider now the comparison of the dividend 516 with a divisor 516 of the same magnitude. In the highest or hundreds order there is no energizing circuit completed and instead a short-circuit is provided around the settable devices, which is traceable from the so volt source through contacts i5, wire 2i, conductor central brush Mb, 5 step Mills, 5 wire iii, 5 wire 2E-b to the 5 step 2- 3 (see the central setting), brush (set at 5) conductor winding device 31, baclrv to wire 2i and the same potential source 2!].

in the tens order where both digits are set to represent 1, a sim lar short circuit exists which is also traceable from 40 volt source iii, contacts it, wire 25, conductor lit, central brush Ht, 1 step lid, 1 wire it, 1 wire tit-43, the 1 step brush (set at l), conductor to winding tQt-n and its related device 5977, back to wire ill and the ll volt current source 2t. Tis circuit also branches from the conductor 25, through the second winding iiQt'b, wire it to the con-- ductor iii in the units order, where it continues through the brush set at 6, the 6 step i which is connected to the wire 32b, 5 wire extending to the 5 step lilo, thence through the connected brush structure liluo., 0 step iii-u, contacts 25:! to the 0 potential source 232.

There is thus a circuit completed through the winding 5Qt-b which will close its contacts 5635M (corresponding to iQtl) to thereby complete the first traced circuit from conductor in the hundreds order, through w. EQh-JJ, contacts iiQti (now closed), wire to the ll potential source 22, thus energizing the relay tom-b as a manifestation that the two numbers compared. are equal.

A comparison of these two equal values serves to illustrate the reason for the connections in the units order between wires 32 and 3! with the 1 unit oilset. if the connections Were made in the same manner as in higher orders, there would have been no completed circuit in the units order, since its brush lie is connected to the 40 volt source. By making a 1 digit offset in the connections, the circuit is directed through 0 volt source, so that the circuit through EiQt-b is completed to in turn complete the circuit through EiQh-b. Let us now consider the circuits involved where the dividend 516 is compared with divisor digit 608. In this case the hundreds digit of the dividend is less than the corresponding digit of the divisor, and no circuit will be completed in the highest order since the related brush it set at the 6 step B l is now connected through the 6 wire to the 6 step lilh whose related brushes l3h-b are not connected to any source of current. In the tens order, a circuit is completed from the volt source it to contacts l4, wire ll, contacts iii, 0 step Hit, (3 wires and 3i!c, 0 step 24, brush it, winding iQt -a (i example), its related unidirectional current flow device er, wire iii and contacts to the i0 volt source This completes a circuit to energize winding (Qt-0 representing that the tens order digit of the dividend is greater than that of the divisor. It will close its related contacts (ifitl but this will have no effect, since the left hand connections to the EQ windings cannot be completed back to a current source, as already stated. The circuit through EQt-o will not extend through the companion winding iQi--b, since the brush 25 in the units order is connected to the 8 step i l and the 8 wire 3i to the 7 step ldu whose connected set of brushes are not connected to any current source. From the three examples whose circuits have just been traced, it will be noted that where the dividend is greater than the divisor, winding Mala-a, for example, will become energized. Where the two amounts are equal, the winding lQhb, for example, is energized, and where the dividend amount is less than the divisor amount, neither of these relays will be energized, so that these two relays by their selective energization or lack of energization will serve to manifest the relationship between the two amounts compared.

From the foregoing, it is also apparent that, where the highest order of the dividend is greater than the corresponding order of the divisor, comparison of lower orders is immaterial and likewise, if the highest order of the dividend is less than the highest order of the divisor, comparison of lower orders is immaterial since the highest order relays cannot be energized. In the case where the two highest orders are equal, there IS a partial circuit completion which is dependent upon comparison conditions in the lower orders. Thus, where the next lower order of the dividend is greater than the divisor, comparison will resuit the completion of a partially established circuit in the highest order to indicate the result. The device is employed in a dividing machine and a set or brushes is provided for each multiple of the divisor, that is, the divisor is set up in the form of the divisor times 1, the divisor times 2, etc. up to the divisor times 3. All related Q/z relays whose related divisor multiples are equal to or greater than the dividend will be energized, and others will not. Inspection of the condition of energization or deenergization of these relays will accordingly enable selection or the highest divisor multiple that is contained in the dividend.

In the drawing one of the sets of divisor settable devices is provided with a second set of windings designated in the hundreds order, for example, 5Qhh-a and 5Qhh--b, and a second brush arrangement b in the units order with the steps 24b thereof connected to the wires 3! through connections 33 in such manner that the steps are connected to correspondingly numbered steps Hlu. This arrangement has lltl1ity where the divisor value represents the 5 times multiple of a divisor which is to be compared with a dividend. The operation may best be explained by assuming a dividend of 516 and a divisor setting of 516, which latter is the 5 times multiple of a divisor 103.2. As traced previously, circuits through the normal settings resulted in energize-- tion of relay 5Qt-b with the resulting energize, tion of 5Qhb to denote equality The second brush 25b in contact with the step 24b in the 6 position is connected through the 6 wire to the 6 ste Ilia. at which brush I la is set so that this circuit extends back to the volt source, and no circuit is completed through 5Qtt-b since both ends of the circuit terminate at the same potential.

If brush 251) had been set at any lower valued digit, for example 5, the circuit extends from the 40 volt source 2!], contacts l5, wir 2|, conductor in, brush Ht, 1 step Hit, 1 wires 29 and 32-1 1 step 24, brush 25, conductor 25, winding 5Qtt-b, wire conductor 2%, brush 2%, 5 step 24b, 5 wire 3|, 5 step I On, connecting brushes l3ua contacts 23 to negative source of current 22. Relay 5Qttb will close its related contacts 5Qttl to complete the circuit through relay EQhh-b. This latter relay by its energization represents that five times the divisor is less than the dividend and that. if operations are not to be extended, the last quotient digit may be rounded. Thus, if 5 times the divisor goes into a dividend exactly, there is no indication while, if there is a remainder, manifestation is made in the nature of a relay energization to indicate that this quotient digit of 5 may be rounded, that is, called a 6 where results are desired in such manner.

What I claim is:

1. Apparatus for comparing two multidenominational numbers for relative magnitude, comprising a first series of settable devices, one

for each order and settable to represent a first.

number, a second series of settable devices, one for each order and settable to represent a second number, a trio of terminals each at a different electrical potential, circuit connections in each order interconnecting the related settable devices of the two said series, a circuit partially completed between the two lowest potential terminals by the settable devices in the highest order and through said connections when both devices are set at the same significant digit, a second circuit completed between the two highest potential terminals by the settable devices in the next lower order and through the related connections, when the device of the first series is set at a higher digit than the device of the second series, means included in said second circuit for completing the said partially completed circuit and a current responsive device included in the latter circuit to represent by its energization that the first number is greater than the second.

2. Apparatus for comparing two multidenominational numbers for relative magnitude, comprising a first series of settable devices, one for each order, settable to represent a first number, a second series of settable devices, one for each order, settable to represent a second number, a trio of terminals each at a different electrical potential, circuit connections in each order interconnecting the related settable devices of the two said series, a circuit partially completed between the two lowest potential terminals by the settable devices in the highest order and through said connections when both devices are set at the same significant digit, a second circuit completed between the two lowest potential terminals by the settable devices in the next two lower orders and through the related connections, when the two devices of the first series are set at the same value as the related devices of the second series, means included in said second circuit for completing the said partially completed circuit and a current responsive device included in the latter circuit to represent by its energization that the first number is equal to the second.

3. Apparatus for comparing two multidenominational numbers for relative magnitude, comprising a first series of settable devices, one for each order, settable to represent a first number, a second series of settable devices, one for each order, settable to represent a second number, a

trio of terminals each at a different electrical potential, circuit connections in each order interconnecting the related settable devices of the two said series, a circuit partially completed between the two lowest potential terminals by the settable devices in the highest order and through said connections when both devices are set at the same significant digit, a second circuit completed between the two lowest potential terminals by the settable devices in the next two lower orders and t through the related connections, when the two devices of the first series are set at the same value as the related devices of the second, or at a higher value, means included in said second circuit for completing the said partially completed circuit and a current responsive device included in the latter circuit to represent by its energize,- tion that the first number is equal or higher than the second.

4. A device for comparing two digits for relative magnitude, comprising a device settable to represent a first digit, a device settable to represent a second digit, a trio of terminals, each at a different electrical potential, circuit connections between said devices, arranged so that when the devices are adjusted with the first digit greater than the second digit, a circuit is completed between the two highest potential terminals; when the devices are adjusted with the digits equal, a partial circuit is established between the two lowest potential terminals; and when the devices are adjusted with the first digit lower than the second digit, no circuit is completed or partially established, means for completing the partially established circuit and current responsive devices in both the completed and partially established circuits to represent by their respective energization that the first digit is greater than or equal to the second digit.

EUGENE KOUZMINE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,074,392 Herbst Mar. 23, 1937 2,230,129 Bryce Jan. 28, 1941 2,243,473 Bryce May 27, 1941 2,328,623 Dickinson Sept. 7, 1943 2,393,386 Leathers et al Jan. 22, 1946 

